Systems using gesture detection apparatuses have become popular that have sensors built in, such as acceleration sensors or angular velocity sensors, and/or optical sensors to detect user's gestures. For example, a system has been known that provides an intuitive play, by detecting a user's gesture through a controller having an acceleration sensor built in, and associates the detection result with a character's motion in a video game (Patent Document 1 and Patent Document 2).
Also, technologies have been proposed to detect a user's motion (such as patting or stroking) on a robot that reproduces a content, and to have the robot reproduce the content depending on the detection result (Patent Document 3); to control a device by combining detection results of user's gestures and voice (Patent Document 4); and the like.
Further, algorithms have been known that identify a user's gesture by determining whether a detected user's gesture is matched with a gesture registered in advance, for example, an algorithm called “Dynamic Time-Warping” (Non-Patent Documents 1-2).